Poker is a card game in which players wager on the value of their hand (typically five cards). The bets form a pot that is claimed by the player with the best hand. The game has many variations.
While the outcome of any particular hand involves considerable chance, most players voluntarily place money into the pot in order to win. They make bets that they believe will have positive expected value, and bluff other players for various strategic reasons. These bluffs and bets are often based on mathematical considerations, and some of them are designed to fool the opponents into thinking they have a weak or strong hand. This is called playing tight and it is believed to be a mark of a good player.
Before the game begins each player must ante or blind. Then a dealer shuffles the cards and deals them to the players one at a time, starting with the player to his left. After the first deal, there are usually several betting intervals. When a betting interval ends, each player shows his hand and the one with the strongest hand wins the pot.
When a player wishes to add more money to the pot, he can “raise” his bet by raising the amount of the bet made by the player before him. The other players must then decide to call his new bet or fold. A player can also check the pot, meaning that he does not wish to increase his bet and will drop out of the round.